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Speed of a boat due to power rower

  1. Jun 24, 2013 #1
    1. The problem statement, all variables and given/known data
    Dear all, I need help with an old exam question. It goes as following:

    The maximum power that a certain athlete can produce is equal to 1 kW. What is the theoretical maximum speed that a rower can obtain in a rowboat with a smooth exterior, a length of 4 meter and a 'wet' surface of 2.8 m^2.


    2. Relevant equations
    No equations are given and I can't think of any. However, the density of air (1.2 kg/m^3), the dynamic viscosity of air (1.8*10^-5 Pa s), the density of water (1000 kg/m^3), the dynamic viscosity of air (0.0010 Pa s) are all given, though it does not say which (if any) I should use.


    3. The attempt at a solution

    I have been attempting to recreate a formula based on the units of the various components. One formula for power = force * speed, so speed=Power/force. For force, which is in newton, I tried multiplying the viscosity of the water with the 'wet' area. The resulting number would have newton as its unit (Pa*s*m^2 is equal to kg*m/s=Newton). However, this left me with a speed in the 6 digits, which I don't think is a realistic answer for a row boat.
    I have tried other combinations as well, but these don't result in the right unit (m/s). Please help.
     
  2. jcsd
  3. Jun 25, 2013 #2

    haruspex

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